Honeywell PowerPoint 4.0 template

1
Approach to Scalable Parallel Processing For
Space-Based Radar
2
Example SAR and GMTI Partitioning/ Mapping/Utiliz
ation
3
Basic SBR Signal Processing
Basic GMTI Processing Flow
Basic SAR Processing Flow
4
Example SAR Processing Assumptions

• Assumed SAR Parameters
• 16 channels (12 Subarrays and 4 Auxiliary
  Channels)
• 400 - 650 Msamples/sec (2.5 - 1.5 nsec per
  sample
• 500 msec receive window (200,000 - 333,000
  range cells per pulse)
• 1 KHZ PRI
• 16,384 pulses in azimuth (16.4sec collection
  time)
• The last 1/2 of the collected samples are used
  as the first 1/2 of the samples for the
• image (processed only through range pulse
  compression and stored)
• 1 beam formed for SAR image input 16,384
  ranges x 16,384 pulses
• 8-bits (1 Byte) per A/D sample
• 64-bits (8 Bytes) for internal data storage for
  complex data (4 Bytes real, 4 Bytes imaginary)
• 32-bits (2 Bytes) for internal data storage of
  real data
• 4/3 oversampling out of the Polyphase
  Channelizer
• 128 Subbands formed only 40 processed

5
Example SAR/GMTI Partitioning on BEP System

• Set local memory per processing element at 128
  KBytes to be able to
• handle 16K FFTs for SAR mode (not double
  buffered)
• For the GMTI mode, the 128 KBytes of local
  memory can handle
• - 256 pulses and 64 ranges per main
  memory access that can be processed in
• the pulse or Doppler dimension
• or
• - 8,000 ranges and 2 pulses worth of
  data per main memory access that
• can be processed in the range
  dimension
• or
• - any combination that maximizes
  throughput by blocking, i.e., effectively
• caching, and striding data for
  optimum performance
• Data can also be partitioned across beams,
  channels, and segments when

6
SAR Processing Flow/Global Memory Accessing (1 of
2)
Loop 16,384 times 16,384 ranges/1 range/loop
Store data from each pulse in global memory
Extract pulse (cross-range) data
Perform cross-range FFT
Store processed data
Range Pulse Compression
16,384 pulses x 1 range x 8 Bytes 131.1 KBytes
16,384 ranges for each pulse
16,384 ranges for each pulse
131.1 KBytes
Loop 16,908 times 268.44 x 106 cells/15.876 x
103 cells/patch
Extract 2D Polar Reformat data
Perform Polar Reformatting
Store processed data
128 pulses x 128 ranges x 8 Bytes 131.1 KBytes
16,384 KBytes
Small overlap to process 126 x 126 patch
Loop 16,384 times 16,384 pulses/1 pulse/loop
Store processed data (transposed)
Extract range data
Perform range FFT
16,384 ranges x 1 pulse x 8 Bytes 16,384 KBytes
16,384 KBytes
7
SAR Processing Flow/Global Memory Accessing (2 of
2)
Loop 16,384 times 16,384 ranges/1 range/loop
Extract pulse (cross-range) data
Perform cross-range FFT
Store processed data
16,384 pulses x 1 range x 8 Bytes 131.1 KBytes
All of this, from cross-range FFT through
Magnituding, can be done with the data in
place, i.e., no need to extract and restore data
until all of the processing is complete. (I
set it up that way because the 2nd half of the 2D
FFT, AutoFocus, and Magnituding appear to be
performed only in the cross-range dimension.
16,384 MBytes
Loop 1024 times 32,768 ranges/32 ranges/loop
Extract pulse (cross-range) data
Perform Auto Focus
Store processed data
16,384 pulses x 1 range x 8 Bytes 131.1 KBytes
131.1 KBytes
Loop 16,384 times 16,384 ranges/1 range/loop
Extract pulse (cross-range) data
Perform Magnitude Function
Store processed data
16,384 pulses x 1 range x 8 Bytes 131.1 KBytes
65.6 KBytes
8
SAR Processing Flow/Global Memory Utilization
Notes 1) For continuous map, the last half of
the previous CPI can be used
as the first half of the data for the next CPI
2) Not exactly sure how this works
with ECCM, collecting training
samples, etc. Obviously, you do not want
a big jammer to mess up the formation
of the SAR image. How to null a
big jammer out without affecting the
image is a major consideration.
3) For onboard DTED processing, I assume the
global memory requirements
would double because two (2)
beams would be formed, an upper beam and a lower
beam with slightly different
look-down angles that could
be used to form the elevation differential ISAR
image 4)
Historically, SAR processing hasnt required the
arithmetic precision of GMTI,
e.g., 4-bit A/D converters and 8-16 bit
data representation in the processing
chain. The memory
requirement is a function of the arithmetic
precision.
Platform Motion
CPIN-1
CPIN1
CPIN
16, 384 pulses
2.2 GBytes complex data
2.1 GBytes available for storing training samples
for AWC (Adaptive Weight Computation) for ECCM
2.2 GBytes complex data
2.2 GBytes complex data
1.1 GBytes of new data from current CPI collection
Total global memory required for SAR (worst case)
9.9 GBytes
This might be able to be reduced to 7.8
GBytes if 2D FFT can be done in place.
Storage of pulse compressed range data for
further processing
Storage of 1st half of 2D FFT result transposed (
corner-turned) through Magnituding
Storage of cross-range FFT processed data
through through polar reformatting
9
Possible SAR Partitioning/Mapping/Utilization (32K
x 32K Image)
10
SAR Processing - Assumptions

• Assumed SAR Parameters
• 16 channels (12 Subarrays and 4 Auxiliary
  Channels)
• 400 - 650 Msamples/sec (2.5 - 1.5 nsec per
  sample
• 500 msec receive window (200,000 - 333,000
  range cells per pulse)
• 1 KHZ PRI
• 32,768 pulses in azimuth (32.8 sec collection
  time)
• The last 1/2 of the collected samples are used
  as the first 1/2 of the samples for the
• image (processed only through range pulse
  compression and stored)
• 1 beam formed for SAR image input 32,768
  ranges x 32, 768 pulses
• 8-bits (1 Byte) per A/D sample
• 64-bits (8 Bytes) for internal data storage for
  complex data (4 Bytes real, 4 Bytes imaginary)
• 32-bits (2 Bytes) for internal data storage of
  real data
• 4/3 oversampling out of the Polyphase
  Channelizer
• 128 Subbands formed only 40 processed
• Assumed Processing Resources
• 32 processing nodes per board
• 64 GFLOPS peak throughput per board
• 48 GFLOPS sustained throughput per board
  (assumed _at_ 75 execution efficiency)

11
SAR Processing Flow/Global Memory Accessing (1 of
2)
Loop 1024 times 32,768 ranges/32 ranges/loop
Store data from each pulse in global memory
Extract pulse (cross-range) data
Perform cross-range FFT
Store processed data
Range Pulse Compression
32,768 pulses x 32 ranges x 8 Bytes 8.4 MBytes
32,768 ranges for each pulse
32,768 ranges for each pulse
8.4 MBytes
Note This sizing assumes that the extracted
data fills the available 8 MBytes of
external memory available on the
Compute Cluster. It might be safer to
assume only twenty-eight (28) ranges per
extraction gt more loops, but the
bandwidth is about the same because
the same amount of data has to be
extracted and re-stored. The same thing
is true for the patch size, except there
is a little more bandwidth required
because of the overlap needed to do
the interpolation. This gets a little
tricky because of the assumed in-place
calculation.
Loop 1060 times 1073.74 x 106 cells/1.012 x
106cells/patch
Extract 2D Polar Reformat data
Perform Polar Reformatting
Store processed data
1012 pulses x 1012 ranges x 8 Bytes 8.2 MBytes
8.2 MBytes
Small overlap to process 1010 x 1010 patch
Loop 1024 times 32,768 ranges/32 ranges/loop
Store processed data (transposed)
Extract range data
Perform range FFT
32,768 ranges x 32 pulses x 8 Bytes 8.4 MBytes
8.4 MBytes
12
SAR Processing Flow/Global Memory Accessing (2 of
2)
Loop 1024 times 32,768 ranges/32 ranges/loop
Note This sizing assumes that the extracted
data fills the available 2MBytes of
external memory available on the
Compute Cluster. It might be safer to
assume only twenty-eight (28) ranges
per extraction gt more loops, but the
bandwidth is about the same because
the same amount of data has to be
extracted and re-stored.
Extract pulse (cross-range) data
Perform cross-range FFT
Store processed data
32,768 pulses x 32 ranges x 8 Bytes 8.4 MBytes
8.4 MBytes
All of this, from cross-range FFT through
Magnituding, can be done with the data in
place, i.e., no need to extract and restore data
until all of the processing is complete. (I
set it up that way because the 2nd half of the 2D
FFT, AutoFocus, and Magnituding appear to be
performed only in the cross-range dimension.
Loop 1024 times 32,768 ranges/32 ranges/loop
Extract pulse (cross-range) data
Perform Auto Focus
Store processed data
32,768 pulses x 32 ranges x 8 Bytes 8.4 MBytes
8.4 MBytes
Loop 1024 times 32,768 ranges/32 ranges/loop
Extract pulse (cross-range) data
Perform Magnitude Function
Store processed data
32,768 pulses x 32 ranges x 8 Bytes 8.4 MBytes
4.2 MBytes
13
SAR Processing Flow/Global Memory Utilization
Notes 1) For continuous map, the last half of
the previous CPI can be used
as the first half of the data for the next CPI
2) I am not sure how this works with
ECCM, collecting training
samples, etc. Obviously, you wouldnt want
a big jammer to mess up the
formation of the SAR image, but
I am not sure how you null a big jammer out
without affecting the image
3) For onboard DTED processing, I assume
the global memory requirements
would double because two (2)
beams would be formed, an upper beam and a lower
beam with slightly different
look-down angles that could
be used to form the elevation differential ISAR
image 4)
Historically, SAR processing hasnt required the
arithmetic precision of GMTI,
e.g., 4-bit A/D converters and 8-16 bit
data representation in the processing
chain. The memory
requirement is a function of the arithmetic
precision.
Platform Motion
CPIN-1
CPIN1
CPIN
32, 768 pulses
8.6 GBytes complex data
2.9 GBytes available for storing training samples
for AWC (Adaptive Weight Computation) for ECCM
8.6 GBytes complex data
8.6 GBytes complex data
4.3 GBytes of new data from current CPI collection
Total global memory required for SAR (worst case)
30.1 GBytes
This might be able to be reduced to 21.4
GBytes if 2D FFT can be done in place.
Storage of pulse compressed range data for
further processing
Storage of 1st half of 2D FFT result transposed (
corner-turned) through Magnituding
Storage of cross-range FFT processed data
through through polar reformatting
14
SAR Processing Flow/Board-Level
Partitioning/Utilization
Each Range PC - Mag node performs range
compression on a pulse by pulse basis sends
processed data to global memory frequency
conversion, polar reformatting, 2D FFT, Auto
Focus, and Magnituding are performed working out
of global memory, and restoring processed data in
global memory on a function by function basis
Each ECCM/AWC/PP Combo Board processes 16 radar
channels with 750 range cells per pulse and 40
subbands per channel forms 1 beam combines 40
subbands each ECCM node outputs 8192 ranges to
each of the next stage receiving nodes
Each PPC Channelizer Board processes 4 radar
channels with 288,000 range cells per pulse
generates 128 subbands 40 subbands are output to
the Global Memory for prcessing in the ECCM nodes
ECCM, AWC, PP Combination Board 1
Range PC, Freq. Conv, Polar Reform, 2D FFT, Auto
Focus, Mag. Board 1
Range PC, Freq. Conv, Polar Reform, 2D FFT, Auto
Focus, Mag. Board 2
ECCM, AWC, PP Combination Board 2
ECCM, AWC, PP Combination Board 3
Range PC, Freq. Conv, Polar Reform, 2D FFT, Auto
Focus, Mag. Board 3
Range PC, Freq. Conv, Polar Reform, 2D FFT, Auto
Focus, Mag. Board 4
ECCM, AWC, PP Combination Board 4
528.4 MBytes/sec between each board and global
memory Aggregate BW 2.1 GBytes/sec
1.15 GBytes/sec input to each PPC board
Max. Sustained T-put per Stage 192 GOPS Used
T-put per Stage 144 GOPS
Max. Sustained T-put per Stage 192 GOPS Used
T-put per Stage 96 GOPS
16 ch x 256 pulses x 288,000 ranges x 4 Bytes
every CPI (0.256 sec) 18.4 GBytes/sec
4 ch x 40 subbands x 1 pulse x 750 ranges
x 8 Bytes output from each PPC board and input to
each ECCM board every PRI (1 msec) 0.96
GBytes/sec Aggregate BW 15.4 GBytes/sec
1 beam x 8192 ranges x 8 Bytes input to each
Range PC board from each ECCM board every PRI
65.5 MBytes/sec Aggregate BW 1.05
GBytes/sec
Training Samples Adaptive Weights
Max. Memory 32 GBytes Used Memory 30.1 GBytes
15
SAR Processing Flow/Node-Level Partitioning/Utiliz
ation
Possible Partitioning/Utilization for Range Pulse
Compression, Frequency Conversion in Range, 2D
FFT, Auto Focus, and Magnituding
Ranges or Cross-Ranges M1 to M32 gt Compute
Cluster 1 Ranges or
Cross-Ranges M1 to M8 gt CNA 1
Ranges or Cross-Ranges M9 to M16 gt CNA 2
Ranges or Cross-Ranges M17 to M24
gt CNA 3 Ranges or Cross-Ranges
M25 to M32 gt CNA 4 Ranges or
Cross-Ranges M33 to M64 gt Compute Cluster 2
Ranges or Cross-Ranges M33 to
M40 gt CNA 1 Ranges or
Cross-Ranges M41 to M48 gt CNA 2
Ranges or Cross-Ranges M49 to M56 gt CNA 3
Ranges or Cross-Ranges M57 to
M64 gt CNA 4 Ranges or Cross-Ranges
M65 to M96 gt Compute Cluster 3
Ranges or Cross-Ranges M65 to M72 gt CNA 1
Ranges or Cross-Ranges M73 to
M80 gt CNA 2 Ranges or
Cross-Ranges M81 to M88 gt CNA 3
Ranges or Cross-Ranges M89 to M96 gt CNA 4
Ranges or Cross-Ranges M96 to M128 gt
Compute Cluster 4 Ranges or
Cross-Ranges M97 to M104 gt CNA 1
Ranges or Cross-Ranges M105 to M112 gt CNA
2 Ranges or Cross-Ranges M113
to M120 gt CNA 3 Ranges or
Cross-Ranges M121 to M138 gt CNA 4
for 1 lt M lt
128 Similarly across all four (4) Compute boards
with the associated change in indexing. (Polar
Reformatting is similar except data is in
Rng-XRng patches Input to Board from ECCM nodes
65.6 MBytes/sec/ECCM board x 4
ECCM boards 262 MBytes/sec gt perform range
compression Range Compression Output to Global
Memory 262 MBytes/sec Post-Range Compression
Processing out of global memory Input to Board
33.6 MBytes per fetch x 128 fetches per function
per board every 65.5 sec 4.3 GBytes/65.5 sec
65.6 MBytes/sec per function per bd.
Output from Board 33.6
MBytes per store x 128 stores per function per
board every 65.5 sec 4.3 GBytes/65.5 sec
65.6 MBytes/sec per function per bd. Aggregate
Bandwidth per board 131.2 MBytes/sec x 4
functions
528.4 MBytes/sec
Compute Board N
Compute Cluster 1
CNA 1
8 MByte Local Data Memory
CNA 2
CNA 3
CNA 4
Compute Cluster 2
CNA 1
8 MByte Local Data Memory
CNA 2
CNA 3
Global Memory
CNA 4
Compute Cluster 3
CNA 1
8 MByte Local Data Memory
CNA 2
CNA 3
CNA 4
Compute Cluster 4
CNA 1
8 MByte Local Data Memory
CNA 2
CNA 3
CNA 4
16
Example GMTI Partitioning/Mapping/Utilization
17
GMTI Processing - Assumptions

• Assumed GMTI Parameters
• 16 channels (12 Subarrays and 4 Auxiliary
  Channels)
• 400 - 650 Msamples/sec (2.5 - 1.5 nsec per
  sample)
• 256 pulses per CPI
• 1 KHZ PRI
• 500 msec receive window (200,000 - 333,000
  range cells per pulse) into the
• polyphase channelizer
• 4/3 oversampling out of the Polyphase
  Channelizer
• 128 Subbands formed only 40 processed
• 6 beams formed
• 10-bits (2 Bytes) per A/D sample
• 64-bits (8 Bytes) for internal data storage for
  complex data (4 Bytes real, 4 Bytes imaginary)
• 32-bits (2 Bytes) for internal data storage of
  real data
• Assumed Processing Resources
• 32 processing nodes per board
• 64 GFLOPS peak throughput per board
• 48 GFLOPS sustained throughput per board
  (assumed _at_ 75 execution efficiency)
• 32 MBytes local data memory per board

18
GMTI Processing Flow/Board-Level
Partitioning/Utilization 1
Each Pulse Compression board outputs 2 beams with
256 pulses and 72,000 ranges Doppler board
receives 6 beams with 256 pulses and 72,000
ranges and outputs 12 beams with 256 Doppler
cells and 72,000 ranges (staggered) STAP outputs
3 beams with 256 Doppler cells and 72,000 ranges
CFAR outputs target detections
Each PPC Channelizer Board processes 4 radar
channels with 288,000 range cells per pulse
generates 128 subbands 40 subbands are output to
the Global Memory for prcessing in the ECCM nodes
Each ECCM/AWC/PP Combo Board processes 16 radar
channels with 1000 range cells per pulse and 40
subbands per channel forms 6 beams combines
40 subbands each ECCM node outputs 30,000 ranges
to global memory for Pulse Compression processing
2 beams x 256 pulses x 72,000 ranges x 8 Bytes
output from each Pulse Compression board to
global memory every CPI 1.15 GBytes/sec
Aggregate BW 3.46 GBytes/sec
ECCM, AWC, PP Combination Board 1
Pulse Comp. Board 1
6 beams x 256 pulses x 72,000 ranges x 8 Bytes
input to Doppler board from global memory every
CPI 3.46 GBytes/sec
Doppler, STAP, CFAR Board 1
ECCM, AWC, PP Combination Board 2
Pulse Comp. Board 2
Max. Sustained T-put per Stage 48 GOPS Used
T-put per Stage 34 GOPS
ECCM, AWC, PP Combination Board 3
Pulse Comp. Board 3
Doppler Output _at_ 6.92 GBytes/sec
Max. Sustained T-put per Stage 144 GOPS Used
T-put per Stage 100.3GOPS
CFAR Input _at_ 1.73 GBytes/sec
Max. Sustained T-put per Stage 144 GOPS Used
T-put per Stage 101 GOPS
STAP Inout _at_ 6.92 GBytes/sec
STAP Output _at_ 1.73 GBytes/sec
4.61 GBytes/sec input to each PPC board
Max. Memory 32 GBytes Used Memory 21 GBytes
16 ch x 256 pulses x 288,000 ranges x 4 Bytes
every CPI (0.256 sec) 18.4 GBytes/sec
4 ch x 40 subbands x 1 pulse x 3000 ranges x 8
Bytes output from each PPC board and input to
global memory every PRI (1 msec) 3.85
GBytes/sec Aggregate BW 15.4 GBytes/sec
16 ch x 256 pulses x 1000 ranges x 40 subbands
x 8 Bytes input to each each ECCM board from
global memory every CPI 5.1 GBytes/sec
Aggregate BW 15.4 GBytes/sec
2 beams x 256 pulses x 90,000 ranges x 8 Bytes
input to each Pulse Compression board from global
memory each CPI 1.44 GBytes/sec Aggregate BW
4.32 GBytes/sec
6 beams x 256 pulses x 30,000 ranges x 8 Bytes
output to global memory from each ECCM board
every CPI 1.44 GBytes/sec Aggregate BW 4.32
GBytes/sec
19
GMTI Processing Flow/Board-Level
Partitioning/Utilization 2
Each Pulse Compression board outputs 2 beams with
256 pulses and 72,000 ranges Doppler board
receives 6 beams with 256 pulses and 72,000
ranges and outputs 12 beams with 256 Doppler
cells and 72,000 ranges (staggered) STAP outputs
3 beams with 256 Doppler cells and 72,000 ranges
CFAR outputs target detections
Each PPC Channelizer Board processes 4 radar
channels with 288,000 range cells per pulse
generates 128 subbands 40 subbands are output to
the ECCM boards
Each ECCM/AWC/PP Combo Board processes 16 radar
channels with 1000 range cells per pulse and 40
subbands per channel forms 6 beams combines
40 subbands each ECCM node outputs 30,000 ranges
to global memory for Pulse Compression processing
2 beams x 256 pulses x 72,000 ranges x 8 Bytes
output to global memory from each Pulse Comp.
board every CPI (0.256 sec) 1.15 GBytes/sec
Aggregate BW 3.46 GBytes/sec
ECCM, AWC, PP Combination Board 1
Pulse Comp. Board 1
6 beams x 256 pulses x 72,000 ranges x 8 Bytes
input to Doppler board from global memory every
CPI (0.256 sec) 3.46 GBytes/sec
ECCM, AWC, PP Combination Board 2
Doppler, STAP, CFAR Board 1
Pulse Comp. Board 2
Max. Sustained T-put per Stage 48 GOPS Used
T-put per Stage 34 GOPS
ECCM, AWC, PP Combination Board 3
Pulse Comp. Board 3
Doppler Output _at_ 6.92 GBytes/sec
Max. Sustained T-put per Stage 144 GOPS Used
T-put per Stage 100.3GOPS
CFAR Input _at_ 1.73 GBytes/sec
Max. Sustained T-put per Stage 144 GOPS Used
T-put per Stage 101 GOPS
STAP Input _at_ 6.92 GBytes/sec
STAP Output _at_ 1.73 GBytes/sec
4.61 GBytes/sec input to each PPC board
Max. Memory 32 GBytes Used Memory 13.1 GBytes
16 ch x 256 pulses x 288,000 ranges x 4 Bytes
every 0.256 seconds 18.4 GBytes/sec
4 ch x 40 subbands x 1 pulses x 1000 ranges x 8
Bytes output from each PPC board to each ECCM
boards every PRI (1 msec) 5.12 GBytes/sec
Aggregate BW 15.4 GBytes/sec
2 beams x 256 pulses x 90,000 ranges x 8 Bytes
from global memory input to each Pulse
Compression board every CPI (0.256 sec) 1.44
GBytes/sec Aggregate BW 4.32 GBytes/sec
6 beams x 256 pulses x 30,000 ranges x 8 Bytes
output to global memory from each ECCM board
every PRI (1 msec) 1.44 GBytes/sec Aggregate
BW 4.32 GBytes/sec
20
GMTI Processing Flow/Board-Level
Partitioning/Utilization 3
Each ECCM/Pulse Compression board outputs 6 beams
with 72,000 ranges per pulse Doppler board
receives 6 beams with 256 pulses and 72,000
ranges and outputs 12 beams with 256 Doppler
cells and 72,000 ranges (staggered) STAP outputs
3 beams with 256 Doppler cells and 72,000 ranges
CFAR outputs target detections
Each PPC Channelizer Board processes 4 radar
channels with 288,000 range cells per pulse
generates 128 subbands 40 subbands are output to
the ECCM nodes
Each ECCM/AWC/PP Combo/Pulse Compression Board
processes 16 radar channels with 90,000 range
cells per pulse and 40 subbands per channel
forms 1 or beams (only 1 forms 2 beams
combines 40 subbands each ECCM node outputs
72,000 ranges to global memory for Doppler
processing
6 beams x 72,000 ranges x 1 pulse x 8 Bytes
output to global memory from the ECCM/Pulse
Compression Boards every PRI (1 msec) 3.45
GBytes/sec Aggregate BW
ECCM, AWC, PPC Comb. Pulse Comp. Board 1
6 beams x 256 pulses x 72,000 ranges x 8 Bytes
input to the Doppler/STAP/CFAR board from global
memory every CPI 3.46 GBytes/sec
ECCM, AWC, PPC Comb. Pulse Comp. Board 2
Doppler, STAP, CFAR Board 1
ECCM, AWC, PPC Comb. Pulse Comp. Board 3
STAP Output (3 beams x 72,000 ranges x 256
Dopplers) _at_ 1.73 GBytes/sec
Max. Sustained T-put per Stage 48 GOPS Used
T-put per Stage 34 GOPS
ECCM, AWC, PPC Comb. Pulse Comp. Board 4
Doppler Output (12 beams x 72,000 ranges x 256
Dopplers) _at_ 6.92 GBytes/sec
CFAR Input _at_ 1.73 GBytes/sec
ECCM, AWC, PPC Comb. Pulse Comp. Board 5
STAP Input (12 beams x 72,000 ranges x 256
Dopplers) _at_ 6.92 GBytes/sec
Max. Sustained T-put per Stage 240 GOPS Used
T-put per Stage 202 GOPS
4.61 GBytes/sec input to each PPC board
16 ch x 256 pulses x 288,000 ranges x 4 Bytes
every 0.256 seconds 18.4 GBytes/sec
Max. Memory 128 GBytes Used Memory 8.66 GBytes
4 ch x 40 subbands x 1 pulse x 3000 ranges x 8
Bytes input to ECCM boards from each PPC board
every PRI (1 msec) 3.07 GBytes/sec )
Aggregate BW 15.4 GBytes/sec
21
Backup Charts
22
Hypothetical Real-Time Adaptive Space-Based Radar
Design
23
Space-Based Radar
Advantages - the ultimate high ground
-- radar horizon gt for airborne or
ground radar - 24-hour all weather
capability (IR sensors cant see
through clouds, optical sensors blind in dark)
- less vulnerable/more survivable than
airborne assets - once launched, lower
logistics costs than airborne assets
(fuel, ground support fighter protection,
etc.) - continuous world-wide coverage with
full constellation of satellites -
High Range Resolution (HRR) with frequency
jumped burst waveforms - SAR (Synthetic
Aperture Radar) - IFSAR (Interferometric
SAR) - DTED (Digital Terrain Elevation
Data) - DAR (Distributed Aperture Radar)
- multi-mission -- GMTI (Joint STARS) -- SAR
(Joint STARS) -- AMTI (AWACS E3-A E-2C)
- GPIR (Ground Penetrating Imaging Radar) -
foliage penetration capability - reduced
downlink requirements with onboard
processing in many cases
Disadvantages/Issues - limited power
generation and power dissipation
capability in space - limited aperture
size (antenna dimensions) - high altitude
(R4 losses) - ionospheric effects
- steep look-down angle/Nadir Hole -
clutter Doppler/clutter Doppler spread
-- function of satellite-target
geometry (earth
background) and platform velocity -
optimal waveform design for target
detection performance and clutter
cancellation -- frequency of operation
(X,L,UHF/VHF) -- polarization (Tx and Rx) --
pulse width, PRF, CPI -- range
resolution/bandwidth -- Doppler resolution --
range ambiguities -- Doppler
ambiguities - constellation --
altitude, inclination, number of
satellites, phasing -
environmental -- radiation,
micro-meteorites, etc. - launch
vehicle capability - initial system cost
24
Considerations for Optimal Onboard Processing
25
GMTI/SAR Mode Switching for SBR